Graphed by Ben Rosenblatt, here are the top 10 most-popular and bottom 10 least-popular Senators, as measured by Morning Consult. Notably, five of the bottom six are up for re-election this November – and all are Republicans.

These five races would seem to present some ripe opportunities – potentially enough to switch control of the chamber. Democrats need to pick up a net three seats – that’s assuming they win the Presidency. If they don’t win the Presidency, there’s no way they will pick up seats, since Presidential and Senate voting are so correlated these days. Since Doug Jones (D-AL) has a tough slog, probably they need to pick up four.

As the campaign heats up, I’ll do what I’ve done in previous years: point out close races where your efforts make the greatest marginal difference. We’ll do Senate and House races. We’ll also expand to state legislative races. Democrats and Republicans will be fighting it out in close states, including Kansas, Texas, Minnesota, and more. The opportunites are the same for both sides, since knife-edge races are the ones where your effort makes the most difference.

Stay tuned!